American Airlines questioned an Ivy League economist Thursday after a woman seated next to him allegedly believed the math equations the professor was scribbling could be connected to terrorism.

The Washington Post reported that Guido Menzio, 40, was on his way from Philadelphia to Ontario for a speaking engagement. Menzio, a professor at the University of Pennsylvania, was escorted off the flight after the woman passed a note to a flight attendant about her suspicions.

Menzio told the Post that he was focused on writing the equation and initially declined to make small talk with the woman. After being taken off the flight, he told the newspaper that "an agent" told him that his seatmate was suspicious of his unidentifiable writing and alerted crew.

The professor said that he explained that the writing and unfamiliar symbols were actually a differential math equation and was eventually allowed to re-board the plane, which was delayed for two hours.

"Menzio is a world-renowned economist, and was on his first leg of his trip to Ontario, Canada to give a talk at Queen's University about menu costs and price dispersion," wrote The Daily Pennsylvanian.

"Last year he won the Carlo Alberto Medal, awarded to the best Italian economist under 40. The dark curly hair and olive skin tone that his seatmate may have thought indicated Middle Eastern descent were actually marks of his Italian roots."

USA Today reported that American Airlines confirmed that the woman, who told flight crew initially that she didn't feel well, did express suspicions about the professor on the flight, operated by Air Wisconsin.

"I thought they were trying to get clues about her illness," Menzio told USA Today. "Instead, they tell me that the woman was concerned that I was a terrorist because I was writing strange things on a pad of paper."

Menzio threw politics into the mix, suggesting that presidential campaign may be playing a part in the rise of alleged xenophobia.

"What might prevent an epidemic of paranoia? It is hard not to recognize in this incident, the ethos of [Donald] Trump's voting base," Menzio stated.